Many different individuals and companies have attempted to create devices that are capable of emulating white light or sunlight. Sunlight is a black body emitter. One device or technology used is light emitting diodes (LEDs).
LEDs may have many advantages over incandescent light sources including lower energy consumption, less heat, longer lifetime, improved physical robustness, smaller size, and faster switching. It may be very expensive and difficult to emulate white light or sun light with LEDs.
Problems with LED lighting include pixelation, where the individual LED lights produce non-uniform light such that you can tell there are individual light sources instead of a continuous source. In order to minimize and decrease the size of a diffused linear LED lighting fixture, the lens or optic needs to be moved closer toward the LEDs and the space between each LED (pitch) needs to also be minimized. Without doing so, unsightly pixilation can occur, which is entirely unacceptable for direct-view installations.
The pixel pitch increases, exponentially, with the introduction of additional colored LEDs as the space between each color becomes the visible pitch that requires mitigation. The simplest way to create a diffused, warm-dimming type, architectural, dynamic lighting fixture is to utilize the fewest number of LED's per increment. The ultimate goal is to represent the visible light spectrum with specific and repeatable spectral values or useful warm-white color temperatures on the Kelvin scale; while following the visual aesthetics of the Planckian locus on the lower/warmer end. There has also been difficulty emulating incandescent lighting colors and dimming performance.
In physics and color science, the Planckian locus or black body curve is the path or locus that the color of an incandescent black body would take in a particular chromaticity space as the blackbody temperature changes. It goes from deep red at low temperatures through orange, yellowish white, white, and finally bluish white at very high temperatures.
Black body sources (approximately any filament bulb or sunlight—but not fluorescent lamps, in general) emit a smooth distribution of wavelengths across the visible spectrum, which means that our eyes and visual system can reliably distinguish colors of non-luminous objects. Subconsciously we adapt to differing bias in the illuminant color, and manage to perceive consistent colors in the artifacts we handle every day (food, clothes, etc.)—despite wide variations in their absolute color.
Artificial sources of light, in particular discharge lamps (sodium, mercury, xenon), LEDs, and fluorescent lamps can have extremely spikey spectral distributions, and this means that their color rendering properties may typically be very poor (even if the overall perceived illuminant color is close to a blackbody color).
In professional lighting, a Color Rendering Index, CRI (sometimes written Ra: Red Average) is often quoted to indicate how accurately that light will portray colors relative to a blackbody source (the sun) at the same nominal color temperature. By definition, all blackbody sources have a CRI of 100. Fluorescent lamps typically have CRIs in the range 55-85, with 80-85 being classed by the manufacturers as ‘good’ or ‘very good’ color-rendering.